Improvement in sewing-machines



3 Shee\s--Sheek1. M l C H A E L H K E R N A U-L. Improvement in Sewing Machines.

Patented Dec. 5,1871.

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IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 121,460, dated December 5, 1871.

To all whom it may concern:

Be it known that I, MICHAEL HEINRICH KER- NAUL, of Berlin, in the Kingdom of Prussia, have invented an Improved Sewing-Machine; and do hereby declare that the following description, taken in connection with the accompanying drawing hereinafter referred to, forms a full and exact specification of the same, wherein I have set forth the nature and principles of my said improvement by which my invention may be distinguished from others of a similar class, to gether with such parts as I claim and desire to secure by Letters Patent-that is to say:

My invention has reference more particularly to that class of sewing-machines that work with a rotating hook, and which are generally known as Wheeler and Wilson machines.

On the accompanying drawing, Figure 1 shows aplan of my-iinproved machine, wherein the cloth plate is shown in dotted lines. Fig. 2 shows a back elevation. Fig. 3 shows a side elevation. Fig. 4 shows a transverse section. Figs. 5 to 11 show detached details.

Similar letters of reference indicate similar parts in each of the'figures.

The eccentric E is formed with a spherical surface, as shown at Fig. 4, upon which the connectingro'd fits with a corresponding spherical recess. The end of the connecting-rod is cast with a fork at Z, Figs. 1 and 3, which when the screws z 2 in the strap are loosened springs open sufliciently for the strap to clear the eccentric. The screw 2 is always screwed up tight, and the fit of the strap upon the eccentric is regulated by the screw z The end 2 of the connecting-rod is secured in the jaw of the arm A of the needlearm spindle or rocker A by means of a taper-pin, s, Fig. 2, fitting with a cylindrical part through the left-hand jaw, and screwed with the reduced threaded portion 8 through the righthand jaw, so that by turning the head m of the pin with a spanner the taper portion is drawn into the taper-eye of the connecting-rod, and thus any backlash through wear is prevented. The pin is secured in position by the lock-nut'm The cylindrical ends of the rocker pass loosely through the uprights S S, and fit into hollows in the coned ends of rim-nuts M M, Fig. 2, which are screwed onto reduced screwed extensions a a of the rocker. The coned surfaces of the nuts M M fit into the correspondingly-coned outer ends of the holes in S S, through which the rocker A passes loosely, and these nuts thus constitute the bearings for the rocker, permitting of perfect adjust-ment both for wear and for adjusting the position of the rocker, while at the-same time they aiford considerable, and, therefore, more durable, bearing surfaces as compared with the ordinary lathe centers usually employed. The nuts M M are screwed up by hand, and are secured in position by lock-nuts m m on the projecting ends of a a, which nuts, as also the nut m and head m of the connecting-rod pin 8, are

all made to fit the same spanner that is used for the screw of the needle-yoke. The construction of the tension-pulley as at present employed has the disadvantage that it requires to be oiled, whereby it is liable to become clogged and to accumulate dirt, more particularly in the felt or cloth disks employed, thus preventing the maintenance of a uniform tension, particularly when the machine has not been worked for some time and the oil has become resinous or congealed. According to the present improvement the two metal disks of the pulley O,Figs l and 2, are screwed upon a boss, of vulcanite horn or material of a similar nature, which requires no oiling, and against the reduced end surface of which bears the end of a sleeve, 0 covering the spiralspring 0 which is acted upon by a nut, K, screwed onto the end of the pin a carrying the pulley. This nut has a small stud, d, which fits into a slot in the end of the sleeve 0 as shown, and thus prevents the latter from turning independently of the nut. By this construction a perfectly-uniform tension is maintained at all times, and a freedom from the accumulation of dirt is insured through. the absence of oiling, and

the covering up of the spring, besides presenting a neater appearance to the eye than the construction heretofore employed. A pin or rod, h, Fig. 4, is made to pass through a cavity, 1, of the front standard L, and to bear with its end upon a rim,r, upon the driving pulley R, against which the rod is pressed by means of a spring, W, in the cavity l bearing against a collar, 70 on the rod, and against the end of the regulating bush :0 screwed into the front end of the cavity, as shown. The rod h passes through the regulating bush, and has formed on its outer end a finger, [1, which during a certain portion of therevolution of the hook G is caused to press against the spool q, and thus, by retarding its rotation, produces any desired degree of tension on the lower thread. For causing such pressure of the finger on the spool to take place at the desired moment, a notch or space, n, Fig. 1, is formed in the rim r of the pulley, so that when this notch arrives at or near its lowest position during the revolution of the pulley 'lt it allows the spring h to force the rod it through it so as to bring the pressing finger h in conta ct with the spool, while on the further rotation of the pulley It the rounded edge of the notch 0 causes the rod h to be pushed back again so to rest upon the rim 1" during the remaining portion of the revolution, during which time, consequently, the finger k is kept away from the spool so as to allow of the free passage of the loop of the upper thread over the spool. As it is only necessary to apply the tension to the lower thread at the moment when the loop of the upper thread is being tightened after it has passed the loop-check brush, it will be seen that by the above-described action the finger h is caused effectually to accomplish its object. For regulating the pressure of the pressing-finger upon the spool, and consequently the degree )f tension on the lower thread, the regulating brush ais screwed further into or out of the recess 1 so as to compress the spring h more or less. This is effected by means of thepressingfinger h itself, which is provided for this purpose with a small pin or stud, c, fitting into a notch in the end of the bush By first turning the finger (after withdrawing the slide-rin g B) from left to right until it lies fiat on the bed-plate, then pulling the finger forward so as to draw the pin 0 out of the notch in the bush, then turning the finger from right to left until the pin 0 can again enter the notch, and, lastly, by bringing the finger into the upright position, the tension will be increased; while by pertorniing'the above operation in the contrary direction the tension will be diminished. Furthermore, if it be not desired to apply the tension at all, this is readily effected by drawing back the finger It so as to bring the pin 0 out of the notch of w, as above described, and then turning the finger so as to lie fiat on the bed-plate, whereby the end of the rod h is drawn out of contact with the rim 1' of the pulley. The slide-ring B is notched at bottom, as shown in Fig. 4, so as to allow of the action of the finger it without interfering with the proper position of the slide-rin g against the spool. Should the machine be intended to do very heavy work with the lower tension it would be necessary to introduce stronger springs than those usually employed both in the presser D and the tension-pulley 0. For medium work, however, sufficient tension can be put on the upper thread with the ordinary spring by screwing up the nut K of the tension-pulley. The application of the lower tension will be of great advantage in machines for household use, where the machine is required to be applicable both for very light work and for very heavy work, (such as for making winter clothing.) For very light work the finger h would be put entirely out of action. As

before described, it will be seen that the puttin in and out of action of the lower tension can be effected instantaneously and with the greatest ease. The bed-plate L has an undercut groove, L, Figs. 3 and 4, formed in it, in which groove slides the head of a screw, '10, sc'ewing through the lip 13 of the slide-rin g and into the nut K, so that by merely slightly turning this nut in one direction or the other the slide-ring is either fixed in position or is capable of being slid forward or backward in the groove; or it can be drawn back entirely out of the groove. When drawn back the slide-ring may, if preferred, be made to turn round sidewise on the screw so as to obviate the necessity of withdrawing it entire] y from the groove, though it is so easily re moved and replaced that this is hardly necessary. The screw to is, by preference, formed with a left-handed thread, so that for fixing the slidering the nut may be turned in the same direction as the ordinary screw. For accurately adjusting the slide-ring relatively to the spool I either provide an adjustable stop, L, Fig. 4, in the groove L secured by a screw, as shown, against which stop the head of the screw 10 bears; or, by preference, I provide an adjustable screw, as at L", Fig. 4*", screwed into the end of the groove, against which the head it bears. The feeding dog is formed as a rectangular block, 1), Figs. 3, 4, 5, and 6, fitting in a corresponding rectangular notch or recess in the front standard L, as shown in Fig. 3. The spindle g carries two eccentrics or cams, one, 6, which may convenientlybe formed on the pulley R, and the other e, fixed on the spindle g behind the rotating hook G, and working in a recess in the standard L. Both eccentrics have exactly the same throw and are in precisely the same angular positions on the spindle, so that as this revolves the two eccentrics raise the dog 19 in a perfectly parallel n1anner for bringing it into action. On the back surface of the dog 1) is a flat bell crank-lever, p p, Figs. 1, 4, and 6, turning on a screw, p screwed into p so as to press the lever tightly against the surface of the dog. The short arm p of the lever carries a stud, a, which presses against a cam surface, r on the pulley R for-effecting the forward or feed motion of the dog when in the raised position. The adjustment of the stud a on the surface of the cam for increasing or decreasing the amount of feed motion is effected by simply raising or depressing the long arm p of the lever, which is caused to move with sufficient friction to insure that it shall not shift unless moved by the hand. The backward motion of the dog is eifected by means of a spring, a, Figs. 1 and 3, fitted into a recess, m in the standard L, and acting upon the dog. For steadying the dog during its vertical motion a small sliding plate, q, situated beneath it, shown detached in plan and elevationv at Figs. 7 and S, fits with its ends in grooves y y, Fig. 3, in the recess of the standard L, and has a pin, 0, fitting through a hole, 0 in the dog, so that this slides up and down upon such pin, while at the same time the plate (1 slides backward and forward with the dog. If a vertical adjustment is desired for the dog, this may be effected either simply by inserting a packing piece underneath the toothed plate 10 thereof, or by dividing the block 19 horizontally into two parts connected together by two screws, so arranged that by turning the screws the upper part may be raised away from the lower part. Such an arrangement is indicated at Fig. 5 the screws p being screwed into the upper part 1) of the dog while they are free to turn in the lower part 0 but are secured therein by pins p fitting in a circular groove in the screw, as shown. The block or segment B of the brush is secured in position by a screw, b Figs. 3 and 11, (by preference with left-handed thread,) having a head, b fitting in an under-cut curved groove, I in the face of the standard L, and screwing through the segment B the front end of the shank having a notch to receive the screw-driver, as shown, so that by slightly turning the screw 1) in one directionor the other the segment B may be either fixed in position or be adjusted up or down, or be withdrawn entirely from the groove L", which is open at top, in a similar manner to the arrangement of the slide-ring B, before described. Instead of passing the brush B from the back of the segment through a closed slot, as heretofore, the slot is formed open at top, as shown at Fig. 11, so that the brush can be inserted from the top, thus greatly facilitating its introduction or removal without injury to the bristles. The brush is secured in position by the screw b. The segment is, by preference, formed at bottom with a rounded projecting edge, I), in order to prevent any catching of the loop of the upper thread thereon. On the under side of the plate T are formed two pins or studs, t, Figs. 9 and 10, which fit accurately into corresponding holes t t formed in the standards L L, and are there secured by means of set-screws b b screwing through the standards L L By this arrangement the cloth-plate. can be removed with great facility by simply loosening the set-screws I) b and raising the plate so as to draw the pins t out of the holes t To facilitate this the presser D is ar ranged to be capable of being turned round in its socket away from the cloth-plate, as is now done in some sewing-machines. In the present instance this is effected by fixing at the top of the presser-arm N a pin, N Fig. 3, or, by preference, with two pins, as at Fig. 3, which, when the presser is in position over the cloth-plate, pass through holes in the presser-head D and thus hold the presser in that position. For turning the presser off the cloth-plate it is raised by hand by means of the head D until this is drawn off the pins N when the presser can be turned and is held in such raised position by the nut D resting upon the top of the pins. I prefer to construct the needle-plate T, Figs. 9 and 10, with two-different sized needle holes, t i on opposite sides of the aperture, through which the teeth of the dog p project, and in forming the two ends of the plate with precisely the same configuration as shown, so that its position can be reversed in the cloth-plate in order to bring the one or the other needle-hole under the needle, as may be required. By this means one single needlepla-te is made to' serve in place of two separate plates of present construction. The needle-plate is secured in position by means of a screw, 12 on the under side of the cloth-plates, arranged either as shown in dotted lines at Fig. 3, or as shown at Figs. 9 and 10. t is a small slit in the edges of the cloth-plate for holding the under thread, in place ofthe spring employed heretofore.

Having thus described the construction, operation, andjrelative arrangement of a sewing-machine with my improvements applied thereto, I will designate in the following clauses those parts of the same which I claim as new and desire to secure by Letters Patent of the United Statesthat is to say:

1. The spindle A, conical nuts M M attached to the ends of the spindle A and made adjustable, as described, and uprights S S, when arranged, operating together, and applied to a sewing-machine, as and for the purposes set forth.

2. The pressing-finger it, when combined and operating in connection with the bobbin 9, as and for the purposes described.

3. The pressing-finger h actuated by means .of a rod, h, operating in combination with the spring h and notched or recessed rim on the driving pulley substantially as and for the purposes set forth.

4. The notched regulatingbush m, the pressingfinger h and pin 0, combined, substantially as set forth.

5. The segment 13 of the loop-check brush, when secured by means of a screw, b having a head fitting into an under-cut groove, L in the standard L, and operating substantially as set forth.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses this 8th day of May, 1871.

' M. H. KERNAUL.

Witnesses:

L. RiiHn,

EDM. REIDER. (134) 

